1. Field of the Invention
The present invention relates to light-guide boards and more particularly, to an improved structure of light-guide board, which comprises a transparent light guide plate made out of an optically transmissive material, and a reflecting layer covered on and formed integral with the back side of the transparent light guide plate to reflect light passing through the transparent light guide plate so as to further enhance the intensity of light and the uniformity in light intensity.
2. Description of the Related Art
Since the invention of electric lamp by Thomas Edison, artificial lighting can be provided at night, and proper lighting can enhance task performance. Nowadays, different lighting fixtures in different shapes for different purposes are commercially available.
Regular lamps commonly use a lamp bulb or lamp tube to produce light. These lamps consume much electric energy and produce heat during operation, hence increasing the ambient temperature. Further, regular incandescent lamps twinkle when giving off light. Twinkling light is harmful to the eyes.
Further, new generation lamps that use LEDs (Light Emitting Diodes) to substitute for conventional incandescent bulbs for the advantages of low power consumption and long working life. Further, an LED is less harmful to the environment because it contains no mercury. However, a LED has the drawback of directional lighting.
In order to avoid directional lighting, multiple LEDs may be arranged together and set in different directions to constitute a lamp. However, using multiple LEDs to constitute a lamp greatly increases the cost. There is another way to constitute a light source by using a backlight module. A backlight module comprises a light-transmissive plate and a reflecting film on the back side of the light-transmissive plate. The reflecting film reflects light from side-mounting LEDs toward the front side of the light-transmissive plate. However, because the reflecting film is covered on the back side of the light-transmissive plate after the light-transmissive plate is made but not formed integral with the light-transmissive plate during fabrication of the light-transmissive plate, a gap exists between the light-transmissive plate and the reflecting film. When light goes through the light-transmissive plate from one lateral side, it touches the reflecting film and is then reflected by the reflecting film toward the front side of the light-transmissive plate. When light goes through the gap in between the light-transmissive plate and the reflecting film, the gap retains a part of light energy, thereby resulting in a loss of light energy occurs.
Therefore, it is desirable to provide a light guide board that eliminates the aforesaid problems.